The Canon's really only sync at 1/125 with studio strobes. Sometimes you can get away with 1/160, but it depends on the brand you're using. If you need higher sync speeds, that's what they make medium and large format cameras for.

If the lighting ratio between the model lights and the flash is far enough apart you won't have a problem.Ie your flash is stopping the motion.You will find that some stusio flashes have a flash duration at full power of 1/160 such as a Speedotron 4800.Others are over 1/1000 such an Elinchrome 600.Keep the model lights dim and your photos will be sharp.Or use multiple heads in one pack to decrease the flash exposure duration.Take a meter reading of the existing light .Let's say you get F8 1/4 sec.Set the studio pack to get an exposure of F11 at fastest synch such as 1/160.You then have a diffence of 5 stops between model light exposue and flash exposure. You should get very little ghosting.Hope this is clear.

The Canon's really only sync at 1/125 with studio strobes. Sometimes you can get away with 1/160, but it depends on the brand you're using.[a href=\"index.php?act=findpost&pid=86268\"][{POST_SNAPBACK}][/a]

Well, no...

1Ds2 does sync at 1/250 with studio flash. Flash duration and sync speed are not the same. Getting a faster flash duration may be as simple as cutting power. The duration of most studio flashes generally gets faster as you cut the flash output. Generally speaking, every stop of output cuts flash duration by 50% as well, so give that a try.

The Canon's really only sync at 1/125 with studio strobes. Sometimes you can get away with 1/160, but it depends on the brand you're using. If you need higher sync speeds, that's what they make medium and large format cameras for.[a href=\"index.php?act=findpost&pid=86268\"][{POST_SNAPBACK}][/a]

As a general statment that is simply wrong.

I had no problems syncing at 1/250 with my 20D, and have no problems now syncing at 1/200 with my 5D and my Bowens studio strobes.

There migth be strobes that have durations longer than 1/200, but then it would not help to have a medium or large format camera to get faster sync would it. And if you have strobes that don't fire at the correct "time" you migth have a problem, but that is IMHO a problem with the strobe, not the camera.

I've shot thousands of frames with Alien Bees and the 1Ds and 1D-MkII at 1/250 with no problems.

Since flash duration is much shorter than 1/250, even at full power, stopping action is not generally a problem. The only time it's really an issue is when shooting outdoors in full sun, and flash is generally only necessary for fill. But in that situation, you can use a reflector for fill, or simply do without flash, and shoot at whatever shutter speed you need.

the canon 1DS II does only sync to studio flash untis on max 1/250 sec.is there a way to increase the sync.i need a higher syn i.e 1/500 or higher..

what do other people use for i.e action/ sports images shot in studio with flash units?

thank you!

c[a href=\"index.php?act=findpost&pid=86266\"][{POST_SNAPBACK}][/a]

generally speaking you can only fire the flash when the shutter is fully open. The shutter consists of two sheets of material - the first leaf covers the sensor before the shutter is released. As the shutter is released this first leaf uncovers the sensor enabling exposure to commence. A set time later the second leaf travels across the sensor to cover it again and stop the exposure. For Canon cameras (except the 1D which has a slightly different mechanism) the second leaf will start to cover the sensor at most 1/250th of a second after the first leaf has fully revealed the sensor - this sets the maximum flahs synchronisation speed. For faster shutter speeds i.e. 1/1000th of a second the second leaf will start covering the sensor before the first leaf has fully revealed it, so you will in effect have a travelling slit revealing parts of the sensor as both leaves travel across the face of the sensor. Therefore, to ensure that the entire sensor is exposed and not just a slits worth you can only use flash below 1/250th second.

If you want to go faster then you will have to use very high power tungsten lighting with a continuous light output and use the same exposure techniques as per daylight photography.

Shorter flash durations will not help as the shutter is not fully open above 1/250th second when the flash fires. - This is wrong (brain was obviously in neutral until I read POMs post)

Another technique is to work in a dark room, open the shutter on bulb setting and then fire the flash at an opportune time. This will give you a shutter speed equivalent to the flash duration.

Medium or large format cameras will probably not help as the delay between the leafs of the shutter being fully open is probably less than 35mm as the travel of the shutter and their mass is greater than for 35mm - though you will need to check the specification of each camera to find out what they can do for you.

Why do you need the higher shutter speed? When exposing for your strobes at a usual iso 100 there is very little ambient light to show and camera shake, the flash light itself is fast enough to freeze any movement. If you are not letting ambient light register, i.e. in a studio setting then as far as the camera is concerned you are taking photos in a totally dark room. There is no light to register anything on the sensor. The flash light at about a 1/1000 happens while the shutter is open and the only light registering on the sensor is during that 1/1000, certainly fast enought to freeze any handshake.

Further to that you have to consider if using radio slaves that some cameras will technically sync flash at a faster speed than the radio slaves can communicate. My cheapo radio slaves will not sync faster than a 1/180.